How do omit values in Matlab when taking R values?

I have a matrix of El Nino Data with Precipitation Data. I have to find the correlation coefficient between El Nino and Precpitation. Some of the precipitation data that came is displayed as -9999 for not recorded.

When writing corrcoef(), how do I do it to where it will omit those elements that have the -9999's in it?

Answer 1

[Sean de Wolski]

So something like:

x = 1:10;
y = 3*(x)+7+rand(1,10)*2; %y = linear function of x plus noise
x([3 7]) = -9999;
corrcoef(x(x~=-9999),y(x~=-9999))